Raided every instance since MC, and I would have to say Wrack from Sinestra.
Only healers got to experience it.
Nothing else I have had to deal with required so much continuous concentration, knowing that a single slip-up over those few minutes would wipe us.

Pretty much every tier has that boss where the raid stacks up and people have to run out at a certain time or else they explode all over everyone. It's a very common mechanic.

What game are you playing, man? Evey single encounter in the game has the ability to wipe a raid 30 seconds in. Are you really saying that the first 30 seconds of every encounter are safe from harm?

I know that most of the raids tier has these kind of mechanics you mentioned but the question was which one is the most unforgiven of them all in your opinion and you really don't need to be rude and insult ppl is it hard to say "I don't agree with you because of etc etc" instead of just throwing insults?

and no not every single encounter that has stuff that can wipe the raid I'm not talking about individual death like failing on avoiding the tornados in Alyzrazor nope I'm talking about more stuff like if someone fail in ultraxion soaking hour of twilight booom all raid is dead not only 1 or 2..got it now? thanks for reading.

Most of the major mechanics I can think of could be overcome with solid play, with the square exception of Defile.

Heigan Dance wasn't that big of a deal, since he didn't enrage and you could 10 man the boss to death.

Archimonde's Death's weren't that bad as long as you didn't have too many at once, you could outplay the death and move on, our first kill had 6 deaths in a 13 minute kill.

Spirit Shock could be recovered from if you were able to interrupt the second one and just healed the person who had aggro for a few seconds.

Most of those "move out or kill everyone" type abilities just took getting used to, but what makes defile unique is it's the only one I can think of that gave you so little reaction time, and one you could simply not prepare for other ways (I know someone mentioned Feng, that's pretty avoidable if you're reading the timers).

- Vaelstrasz where he ignited someone who would explode after ~10 seconds. Not moving away from raid was a wipe.
- Solarian has got a similar ability.
- Ebonroc dodging/resisting taunt and heal to full hp in 3 hits.
- Failing a cooldown on the maintank at Sartharion 3d.

While I agree with so many things you guys have said, it has to be Corrupted Blood from Hakkar in ZG (original). I mean, it's one thing for this buff to wipe your raid....but to cause server-wide epidemics...DAMN THAT'S UNFORGIVING/ABLE

Have to say High Astromancer Solarian. If you failed on the explosion spell, that was a huge mistake and punishable by -50 dkp.

Just wanted to say that. This is just as unforgiving as Defile except Solarian was a piss easy boss and LK wasn't. One mistake on Solarian with that explosion crap (don't know the spell anymore) and you wiped. There are plenty more of these mechanics.

Defile wasn't less forgiving. If a few people stood in it you could still recover.

During progression when healing was pretty intense, one mistake and that was it, wipe lol.

I used to sit on this boss because of my shitty computer at the time, besides the stupid long load times, stuff like dying and ghost spawning in Teron would just freeze up everything... if I had ghosts on me, goodnight sweet prince..

So you ask about specific mechanics and you the OP just point out 3 in general without mentioning said mechanics...ok.

LK's Defile. standing in the wrong place like noob = raid over.

It was easy to avoid, but very unforgiving when someone made the mistakes, specially considering the consequences were not only for that player that made said mistake, but for the rest of the raid aswel.

you could still live if defile grew a little...just had to be lucky and not have it grow and hit others...

what about archimondes soulstones...
1 person screws up and dies, doesn't hit tears of the goddess / to early or to late....drops into a fire, gets feared into fire etc while healers are getting knocked into the air... so on...
annoying F'ing fight.

you had to hope he only did his mana drain if 1 person dies...or it's a cascade effect...1 person dies, then he kills another with soulstone ability...then another then 5 then...raid dead. but hey, its another bc boss

Not to play the grammar nazi here, but do you mean "unforgiven" or is it really "unforgiving"? Apologies if it has been asked before.

However, I both cases, again, not to jump on the bandwagon, but Defile has always taken the cake for me. All the others I could think of could usually still be mitigated if you had a fuckup or two, but seeing the EXACT SAME SCHMUCK screw it up several times in a row every single lockout and that black piss puddle of doom grow planted a permanent image of hate in my brain, makes we wake up in a cold sweat at night, having Vietnam-type flashbacks.

Yeah.

Originally Posted by DarkTZeratul

There's this concept called "fun." I know it's foreign to most of the people on this forum, but perhaps you should look into it; there's a school of thought that suggests it's integral to why people play games.